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Documentation guide

How to write docs that people actually read

Good documentation is one of the most underrated skills in tech. The people who write clearly ship faster, prevent misalignment, and build trust across teams without being in every meeting.

Why documentation matters more than most people think

Documentation is asynchronous communication at scale. A well-written runbook lets an on-call engineer fix an incident at 3am without waking anyone. A clear PRD prevents a month of misaligned engineering work.

Good documentation is a multiplier — it makes your work available to everyone, forever.

The documentation types every tech team needs

Each type serves a different reader at a different moment. Using the right format signals that you understand who you are writing for.

PRD

Product Requirements Document

What to build, why, for whom, and how to know if it worked.

TDD

Technical Design Doc

How to build it — architecture decisions, trade-offs, implementation plan.

Runbook

Runbook

How to operate it — deployment, monitoring, incident response procedures.

API docs

API Documentation

What the API does, endpoints, authentication, request/response examples.

ADR

Decision Log (Architecture Decision Record)

Why major decisions were made — context is lost when people leave.

Wiki

Wiki / Knowledge Base

Reference information for the team — onboarding guides, processes, FAQs.

Principles of good documentation

These apply to every doc you write, regardless of the type or audience.

Written for the reader, not the writer

Before writing, ask who will read this, when, and what they need to know.

State the context first

What is this document? Why does it exist? Who is it for?

Short sentences, active voice

'The user clicks Save' beats 'The Save button is clicked by the user'.

Specific over vague

'Under 200ms response time' beats 'fast response time'.

Dated and owned

Every document should have a last-updated date and an owner. Undated docs become untrustworthy.

The PRD one-page format

A one-page PRD forces clarity. If you need more than one page, the thinking is probably not done yet.

Problem

What user problem are we solving?

Include data

Goal

What does success look like?

Metric + target + timeline

Non-goals

What are we explicitly not solving?

Solution

What are we building?

2–3 sentences

User stories

As a [user], I want [action] so that [benefit]

Out of scope

What will not be built in this version?

Open questions

What needs to be decided before we start?

Writing for different audiences

The same information needs to be written differently depending on who is reading it and why.

For Engineers

Be precise. Specify exact behavior. Include edge cases. Expect questions about implementation.

For Stakeholders

Be brief. Lead with the outcome. Keep technical details in an appendix.

For Users

Be conversational. Use plain language. Show examples.

The documentation habit

Document as you go, not after. Writing documentation after the fact produces worse docs and rarely happens.

The test

Could a new team member use this document to understand and do the thing without asking you?

Next steps

Build your technical communication skills

Good documentation starts with good writing. Learn how to write clearly and precisely for technical audiences.

Technical writing guide